2003 Tiburon GT, RPM's drop way down and idles rough at stop's?

500 is too low for and automatic in drive
normal idle is 850-900 and should not drop below 800 in drive as the ECM should be adjusting for the drive load when in gear
take it in to an accredited service shop that works on your make of vehicle and have the problem diagnosed properly and quote

fuel injectors may be clogged and not spraying properly

run the fault codes
check for vacuum leaks on all vacuum hoses
check fuel pressure
use quality injector cleaner

When was the last time a full tune up have been done? A bad intake gasket would do that.

There r 2 cables on a gt 6 speed that r located at the top of the engine in back.. Do not touch the rear cable unless ur tibrron is shifted hard. The front cable is ur drift idle, theyre 2 nuts tightend den to secure it at a certian level , untighten the nuts and simply ajust the 2 nuts backwards do the cable isnt so tight and allows the engine to drop idle wen accelerater isnt pressed. Then do the same to the rear cable(2nd) cable untill u have ur tibron sounding just right..only sol_tion

Hello
The engine and transmission in this cars drivetrain are fully electronically controlled by a computer called the PCM (Power Train Control Module). Whenever a problem like this occurs the computer stores a record of the problem in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s)

If your car has a manual transmission, it is probably the clutch getting ready to burn our

have you changed your fuel filter in the last year or so, if not. do it. a plugged up fuel filter will cause a lot of issues also. it can cause stalls, hesitation and stumbling.

its gonna be your clutch i had the same problem, when i floor it the rpms would go high then drop and take off i replaced it and it runs fine know

This generally indicates a vaccumn leak, or sticking idle air control valve.